Nude Turntable Project

Henry, Don't own a Garrard 301. Do own a highly modified Lenco L75. In fact the only parts from a stock Lenco that I use are the motor, the idler arm and wheel, and the platter. Where there is a motor, there is an electromagnetic field. Thus I am sure that one would be detected with a detector in the vicinity of the motor. However, I use the PTP plate, which is 4mm of solid steel between the motor and the underside of the platter. Moreover, there is about 2 to 3 inches of space between the motor and the platter, and the platter itself is heavy aluminum. So, the shielding is at least "pretty good", and the physical distance would help as well. These fields generally fall off in accordance with an inverse square law; the strength is inversely proportional to the square of the distance. In DD's with coreless motors, like the TT101 and the L07D, the potentially radiating elements of the motor are particularly up close to the platter.

Stick your detector down there, and see what that does. Also, the thick platter gives distance from any possible problem up on the platter surface.

Hi Lewm
I fear for the life of my 2 year old Samsung Galaxy if I stuck it in there. a little curious but not that much.....
My daughter just expensed a new IPhone to me and my son a Samsung Note.
They both turn 19 on Friday this week - how could I refuse.
My phone now needs to last a couple more years.
btw - Drinking age in Ontario is 19 - maybe they will buy me a bottle of wine in return.

I suspect any levels I measured came from the cartridge - I was only six inches away from it.

I am however surprised at Dovers comment.

I dont think it is ideal to have electromagnetic fields floating around the cartridge, irrespective of what type of TT is used.

I mean considering he uses a Dynavector tonearm and preferred ET2 Magnetic damping. :^)

Cheers

I currently have a L07d in a thousand pieces. It uses extensive complex shielding around the motors many parts. Quite necessary I think, since the coils are close to the upper platter surface and are oriented vertically, focusing their flux up and down as opposed to horizontally on some other designs.

Chris, the increase in flux strength on the SP10 MK2 when stopped is due to the brake solenoid. Powered at stop, off when running.
I don't bother with the brake at all, using the EM braking of the motor itself to pull down the platters speed at stop.

Chris, the increase in flux strength on the SP10 MK2 when stopped is due to the brake solenoid. Powered at stop, off when running.

two comments Richard

1) You confirmed that this app on my phone actually works. this is kind of cool.
2) I'm impressed with your findings.

I currently have an L07d in a thousand pieces.

I look forward to reading about how you fit an ET2 on that. :^)

But Boy, would I really like for someone like you to get yours hands on a thread drive design TT - NOT - a belt drive design that has been converted to thread.

I would love to read your impressions ...

Cheers

09-18-13: Ct0517
I am however surprised at Dovers comment.

I dont think it is ideal to have electromagnetic fields floating around the cartridge, irrespective of what type of TT is used.

I mean considering he uses a Dynavector tonearm and preferred ET2 Magnetic damping. :^)

Ct0517 - your comments are incorrect.
Though I own a Dynavector arm I have not used it for a long time. It is handily outclassed by my Fidelity FR64S, Naim Aro and Eminent Technology ET2 arms.
Please refer to my post in your ET2 thread...

05-16-13: Dover
By the way I still own a Dynavector 501 which has a very high horizontal effective mass, and whilst the bass is quite punchy, the musical timing, soundstaging, and resolution is well down on both my Naim Aro and Fidelity Research FR64S ( yes I own 2 of these as well ).

Another correction:
Very minimal magnetic damping is used on my ET2, none on the Denon 103 set up, and it is well away from the cartridge and cable. This too was explained in your ET2 thread.

03-03-13: Dover
The configuration I use is:
Decoupled counterweight in the horizontal mode ( spring bypassed )
Lightened tonearm
Minimal magnetic dampening